Valves often develop leaks as they age. Leaking valves can be annoying, wasteful, and can cause damage in residential settings, but can be far more problematic in industrial applications. Factory lines may need to be shutdown to repack or replace valves resulting in lost production and unnecessary downtime. Leaks can cause environmental damage and safety issues. Steam leaks can scald and even kill workers. The Environmental Protection Agency (EPA) is concerned about pollution resulting from leaky valve stem seals in factories and oil fields. In extreme cases, such as semiconductor manufacturing, even microscopic leaks can be fatal—breathing tanks and hazmat suits are often required to clean up after leaks are detected in semiconductor foundries.
Most traditional valves usually have two moving seals: (1) the Seat where the flow of material through the valve is allowed, controlled, and shut off, and (2) the Stem seal that keeps the material from leaking out of the hole for the valve handle. Studies have shown that some high percentage of the leaks encountered in real world valves are associated with the stem seals because they tend to entrain dirt and grit which can erode the mating surfaces over time.
Traditional valves contain stem seals that often degrade or leak over time. Previous seal-less valves often employed bending or flexing components such as bellows or membranes that can degrade or fatigue and also leak long term. Additionally, previous generations of magnetic valves usually contained internal magnets and/or operated in a linear solenoid type manner making high temperature operation difficult to achieve, and often requiring continuous power to maintain their position.